A diffusion furnace capable of improving the uniformity of square resistance of silicon wafers

Abstract

The present invention belongs to the field of semiconductor diffusion process equipment, and discloses a diffusion furnace capable of improving the uniformity of square resistance of silicon wafers, comprising: a furnace door, a furnace body, an air inlet pipe, an air outlet pipe and a heat insulation part, one side of the furnace body is open, the furnace door is installed at the opening of the furnace body, one end of the furnace door is hinged to the furnace body, the air inlet pipe and the air outlet pipe are respectively connected to the furnace body, there are at least two air inlet pipes, and a heat insulation part is movably arranged on one side of the furnace body near the furnace door. This scheme can increase the gas concentration and residence time at the furnace mouth, and adopts a multi-channel air inlet pipe to improve the gas uniformity at the furnace mouth, thereby improving the uniformity of the square resistance diffusion of silicon wafers near the furnace mouth.

Description

Technical Field

[0001] The invention relates to the field of semiconductor diffusion process equipment, and in particular to a diffusion furnace capable of improving the uniformity of square resistance of silicon wafers. Background Art

[0002] Diffusion furnace is one of the important process equipment in the front process of semiconductor production line, and is often used in large-scale integrated circuit and power electronics industries. In the photovoltaic industry, diffusion furnace is mainly used for solar cell thermal diffusion process, through which preheated process gas containing P and N is diffused to silicon wafer to form solar cell junction, and the quality of the junction directly affects the conversion efficiency of solar cells, so the quality of diffusion process plays a key role in the quality of solar cells.

[0003] During the diffusion process, the uniformity of diffusion resistance is a key indicator of the diffusion process, and temperature and airflow are two key factors affecting uniformity. It has been verified that the uniformity of diffusion furnace mouth resistance is poor, and the main reasons affecting the uniformity of the furnace mouth are the following two aspects:

[0004] First of all, the furnace door of a traditional diffusion furnace is generally sealed with a rubber sealing ring. Rubber is prone to expansion and deformation at high temperatures, and the sealing ring needs to be cooled. The cooling of the furnace door will affect the diffusion of the process gas. The diffusion capacity of gas molecules decreases at low temperatures. At this time, the diffusion capacity of process gas molecules at the furnace mouth is lower than that in the middle of the furnace body, resulting in a larger diffusion resistance at the furnace tail.

[0005] Secondly, the traditional diffusion furnace reaction tube has only one air inlet, which is affected by the gas flow direction, and it is easy to form a difference in process gas content between the tube mouth and the tube tail. That is, the concentration of the diffusion process gas at the tail of the reaction tube is large, while the concentration of the process gas at the furnace mouth is relatively small. Since the temperature at each position in the diffusion furnace is constant, the greater the concentration of the process gas, the smaller the diffusion resistance. As a result, the rear resistance decreases from the furnace mouth to the furnace tail after the above-mentioned diffusion method is used, and the consistency of the diffusion resistance in the furnace body is poor. Summary of the invention

[0006] The object of the present invention is to provide a diffusion furnace capable of improving the uniformity of square resistance of silicon wafers, so as to improve the problem of poor uniformity of square resistance of silicon wafers at the furnace mouth in the above-mentioned prior art diffusion process.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides a diffusion furnace capable of improving the uniformity of square resistance of silicon wafers, comprising a furnace door, a furnace body, an air inlet pipe, an air outlet pipe and a heat insulation part. One side of the furnace body is open, the furnace door is installed at the opening of the furnace body, one end of the furnace door is hinged to the furnace body, the air inlet pipe and the air outlet pipe are respectively connected to the furnace body, there are at least two air inlet pipes, and the heat insulation part is movably arranged in the furnace body near the furnace door.

[0009] Furthermore, the heat insulation part is a heat insulation board, a through hole is opened in the middle of the heat insulation board, and the outer edge of the heat insulation board is in contact with the inner wall of the furnace body.

[0010] Furthermore, it also includes a connecting rod and a stop part, one end of the connecting rod is fixedly connected to the furnace door, the upper end of the furnace door is hinged to the furnace body, the other end of the connecting rod is fixedly connected to the insulation board, the lower side of the inner wall of the furnace body protrudes upward to form a stop part, the stop part includes a coupling surface and a stop surface, the coupling surface abuts against the lower edge of the insulation board, and the stop surface abuts against the side of the insulation board to limit the insulation board from moving away from the furnace door.

[0011] Furthermore, the air outlet pipe is communicated with the lower end of the furnace body, and the air outlet pipe is arranged between the furnace door and the heat insulation board.

[0012] Furthermore, two air inlet pipes are provided on the end surface of the furnace body away from the furnace door, and the two air inlet pipes are symmetrically arranged relative to the axis of the furnace body.

[0013] Furthermore, it also includes a diversion structure, which is arranged on the side away from the furnace door, and the diversion structure divides the furnace body into multiple chambers step by step.

[0014] Furthermore, the diversion structure includes a fixed rod and multiple diversion plates, the multiple diversion plates are arranged in parallel and vertically fixedly connected to the fixed rod, both ends of the fixed rod are fixedly connected to the furnace body, and the side edges of the diversion plates are fixedly connected to the side walls of the furnace body.

[0015] Furthermore, the multiple diverter plates include a first diverter plate, two second diverter plates, and four third diverter plates. The multiple diverter plates are aligned and arranged near one end of the furnace door. The length of the second diverter plate is between the length of the first diverter plate and the length of the third diverter plate. The length of the third diverter plate is less than the length of the second diverter plate. The first diverter plate is arranged on the axis of the furnace body, and the two second diverter plates are respectively arranged on the axes of the two air inlet pipes. The third diverter plate is arranged on the adjacent two sides of each of the second diverter plates, and the spacing between the multiple diverter plates is equal.

[0016] Furthermore, it also includes a guide plate, which is fixedly arranged above the middle section of the inner wall of the furnace body.

[0017] Furthermore, a quartz reaction tube is fixedly arranged on the inner wall of the furnace body.

[0018] The present invention discloses the following technical effects:

[0019] The installation of heat insulation board reduces the temperature drop gradient at the furnace mouth, increases the gas concentration and residence time at the furnace mouth, and adopts multi-way air inlet pipes to improve the gas uniformity at the furnace mouth and enhance the uniformity of the square resistance diffusion of silicon wafers near the furnace mouth. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0021] Figure 1 It is a schematic diagram of a first embodiment of the structure of a diffusion furnace of the present invention;

[0022] Figure 2 for Figure 1 A right side view of the cross section of the first embodiment of the diffusion furnace shown along line AA;

[0023] Figure 3 for Figure 1 The left side view of the cross section of the first embodiment of the diffusion furnace shown along line BB;

[0024] Figure 4 for Figure 1 The left side view of the cross section of the first embodiment of the diffusion furnace shown along line CC;

[0025] Figure 5 for Figure 1 A right side view of a cross section taken along line CC of the first embodiment of the diffusion furnace shown;

[0026] Figure 6 for Figure 1 A partial enlarged view of area D of the first embodiment of the diffusion furnace shown;

[0027] Figure 7 It is a schematic diagram of a second embodiment of the structure of a diffusion furnace of the present invention;

[0028] Figure 8 It is a schematic diagram of a third embodiment of the structure of a diffusion furnace of the present invention;

[0029] Fig. 9 It is a schematic diagram of a fourth embodiment of the structure of a diffusion furnace of the present invention.

[0030] Description of reference numerals:

[0031] 1 is a furnace door; 2 is a connecting rod; 3 is a heat insulation board; 4 is a furnace body; 5 is a guide plate; 6 is a diversion structure; 7 is an air inlet pipe; 8 is an air outlet pipe; 9 is a quartz reaction tube; 31 is a through hole; 41 is a stopper; 61 is a fixing rod; 62 is a first diverter plate; 63 is a second diverter plate; 64 is a third diverter plate; 65 is a guide part; 66 is a heating part; 411 is a joint surface; 412 is a stopper surface. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] First embodiment:

[0035] Reference Figures 1 to 6 As shown, the present invention provides a diffusion furnace capable of improving the uniformity of square resistance of silicon wafers, comprising a furnace door 1, a furnace body 4, an air inlet pipe 7, an air outlet pipe 8 and a heat insulation part. The furnace body 4 is open on the left side (i.e., the furnace mouth), and the furnace door 1 is installed at the left opening of the furnace body 4. One end of the furnace door 1 is hinged to the furnace body 4. The furnace door can be opened and closed under the action of a driving structure to open and close the left opening of the furnace body 4. The air inlet pipe 7 and the air outlet pipe 8 are respectively connected to the furnace body 4. There are at least two air inlet pipes 7 for inputting and outputting process gases. The furnace body 4 is movably provided with a heat insulation part near the furnace door 1. The heat insulation part is a material capable of blocking the transfer of heat flow, and a heat insulation part made of heat insulation materials such as asbestos board and vacuum board can be used. In addition, the diffusion furnace has a heating device, which can be externally heated or heated inside the furnace body. The heating device belongs to the prior art and will not be described here.

[0036] The main function of the heat insulation board is to insulate the furnace door 1. The low-pressure diffusion process has high requirements on the airtightness of the diffusion furnace. If the airtightness of the furnace door 1 is to be maintained, the area near the furnace door 1 needs to be cooled. Under normal circumstances, the gas diffusion coefficient is related to the temperature, pressure, concentration and properties of the material of the system. Under the same conditions, the lower the temperature, the slower the gas diffusion. If the heat insulation part is not provided, the temperature gradient at the furnace door 1 will drop too quickly, which will cause the uniformity of the silicon wafer square resistance at the furnace mouth to decrease, thereby increasing the resistance of the silicon wafer and causing the consistency of the diffusion square resistance to deteriorate. The heat insulation part is provided to block the thermal effect of the middle part of the furnace body 4 on the furnace door 1, and at the same time increase the residence time and disturbance of the process gas at the furnace mouth, which can prevent the temperature of the furnace door 1 from being too high and reduce the temperature drop gradient of the furnace mouth. At the same time, it has a buffering and drainage effect on the airflow reaching the furnace mouth, which is beneficial to improving the uniformity of the silicon wafer square resistance.

[0037] In addition, the traditional diffusion furnace has only one air inlet pipe, while the present solution provides at least two air inlet pipes, which evenly introduce the process gas. In this way, compared with one air inlet pipe, the process gas entering the diffusion furnace is diverted through the air inlet pipe. It can be understood that the air inlet pipe can be set not only at the rear end of the furnace, but also in the furnace or at the furnace mouth. Multi-directional air intake can achieve uniform diffusion of the process gas.

[0038] A further optimized solution is provided, in which the heat insulating part is a heat insulating board 3, the materials on both sides of the heat insulating board 3 are quartz, and a heat insulating material is filled between the two layers of quartz. The heat insulating material may be mineral wool or other materials. This design enables the heat insulating board 3 to have high temperature resistance and heat insulation properties. The outer edge of the heat insulating board 3 is fitted with the furnace body 4, and a through hole 31 is provided in the middle of the heat insulating board 3. The through hole 31 serves as a gas channel, and the process gas can flow in this gas channel.

[0039] A further optimized solution is provided, the diffusion furnace further comprises a connecting rod 2 and a stopper 41, one end of the connecting rod 2 is fixedly connected to the furnace door 1, the upper end of the furnace door 1 is hinged to the furnace body 4, and the other end of the connecting rod 2 is fixedly connected to the heat insulation board 3. It can be seen that the furnace door 1, the connecting rod 2 and the heat insulation board 3 are arranged as a combination, which can be flipped outward around the upper left corner of the furnace body 1 together, thereby increasing the convenience of operation. The lower side of the inner wall of the furnace body 4 protrudes upward to form a stopper 41, and the stopper 41 comprises a bonding surface 411 and a stopper surface 412. The bonding surface 411 abuts against the lower edge of the heat insulation board 3, and the stopper surface 412 abuts against the side of the heat insulation board 3 to limit the heat insulation board 3 from moving away from the furnace door 1, and at the same time, it can prevent process gas and heat from flowing out from the lower edge of the heat insulation board 3. Due to the provision of the stopper 41, the height of the heat insulation board 3 in the furnace body 4 is increased, and interference between the heat insulation board 3 and the furnace body 4 can be prevented when the furnace door 1 is flipped outward.

[0040] Under normal circumstances, if the stopper 41 is not provided, the heat insulation board 3 will not be able to be opened normally. In this case, the solution is to increase the diameter of the furnace body 4 at the furnace door 1, the furnace door 1 is arranged at the large diameter end, and the heat insulation board 3 is arranged at the small diameter end, so as to facilitate the furnace door 1 and the heat insulation board 3 to be opened at the same time. The stopper 41 is added to the present solution without changing the diameter of the furnace body 4 at the furnace door 1, so that the furnace door 1 and the heat insulation board 3 can be opened at the same time, thereby saving the use space and working space, and can be realized by improving the traditional diffusion furnace, and has good economy.

[0041] Further optimization scheme, an air outlet pipe 8 is provided on the left side of the furnace body 4, the air outlet pipe 8 is connected with the lower end of the furnace body 4, and the air outlet pipe 8 is provided between the furnace door 1 and the heat insulation board 3. When the process gas flows through the furnace mouth, because the outer edge of the heat insulation board 3 is closely attached to the inner wall of the furnace body 4, and a gas channel is left in the middle, the upper process gas reaching the heat insulation board 3 will move downward, and the lower process gas will move upward, and the process gas will be concentrated through the through hole 31 and then discharged from the air outlet pipe 8, so as to further increase the residence time of the process gas at the furnace mouth and improve the uniformity of the square resistance of the silicon wafer at the furnace mouth.

[0042] To further optimize the solution, two air inlet pipes 7 are set on the right side of the furnace body 4 (i.e., the furnace tail). The two air inlet pipes 7 are arranged symmetrically up and down relative to the axis of the furnace body 4. The two air inlet pipes 7 are usually set at four equal parts of the furnace body. At this time, the flow rates through the two air inlet pipes 7 are equal. Compared with setting a single air inlet pipe 7, the process gas can flow into the furnace body 4 more evenly, so that the process gas is more evenly distributed at the furnace tail, which is beneficial to improving the uniformity of the square resistance of the silicon wafers at the furnace tail.

[0043] Further optimizing the scheme, the scheme also includes a diverter structure 6, which is arranged on the right side of the furnace body 4 and on the left side of the air inlet pipe 7. The diverter structure 6 can be a honeycomb diverter plate, a mesh diverter plate, or a diverter plate evenly distributed in parallel, or a combination of the above structures, etc. Since the process gas directly enters the furnace tube from the tail air inlet pipe of the furnace tube during the diffusion process of the existing diffusion equipment without dispersion, the air flow in the furnace tube is uneven, and finally the square resistance uniformity after diffusion is poor. By adding a diverter structure 6 to the tail air inlet pipe of the furnace, the air flow uniformity can be effectively improved, and finally the effect of improving the square resistance uniformity can be achieved.

[0044] To further optimize the scheme, the diversion structure 6 of this scheme includes a fixed rod 61 and multiple diversion plates, the multiple diversion plates are arranged horizontally, the fixed rod 61 is vertically fixedly connected to the diversion plate, both ends of the fixed rod 61 are fixedly connected to the furnace body 4, and the side of the diversion plate is fixedly connected to the side wall of the furnace body 4. The fixed connection can be understood as a fixing method such as welding. The fixed rod 61 mainly plays a reinforcing role, and can also play a diversion role. The provision of the diversion plate can divide the airflow into multiple parts, thereby further improving the uniformity of the airflow.

[0045] A further optimized solution is provided, wherein the plurality of diverter plates include a first diverter plate 62, two second diverter plates 63 and four third diverter plates 64, the left ends of the diverter plates are aligned, the length of the first diverter plate 62 is greater than the length of the second diverter plate 63, the length of the second diverter plate 63 is greater than the length of the third diverter plate 64, the length of the first diverter plate 62 is less than one third of the length of the furnace body 4, and the right end face of the first diverter plate 62 is fixedly connected to the right side wall of the furnace body 4, so as to evenly divide the process gas into two upper and lower parts, so as to better utilize the space inside the furnace body 4, the first diverter plate 62 is arranged on the axis of the furnace body 4, the two second diverter plates 63 are arranged on the axes of the two air inlet pipes 7, the third diverter plate 64 is arranged on both sides of each second diverter plate 63, the two air inlet pipes 7 will generate two air flows, and the above-mentioned arrangement can gradually divide the two air flows into four parts, and then into eight parts, so that the gas is evenly distributed inside the furnace body 4.

[0046] When the process gas flow is small, the existing honeycomb or mesh diverter plates cannot fully disperse the process gas. This solution can solve the shortcomings of the existing diverter plates. This diffusion furnace can gradually disperse the airflow, and the effect is better when the gas flow is small.

[0047] According to a further optimized solution, the diffusion furnace further includes a guide plate 5 , which is fixedly arranged above the middle section of the inner wall of the furnace body 4 .

[0048] The guide plate 5 can be set as an arc-shaped surface extending along the inner wall of the furnace body 4, the arc-shaped surface faces the air inlet pipe 7, and the preferred angle of the arc-shaped surface is 90 degrees. The material of the guide plate 5 is quartz, and the guide plate 5 is set in the middle of the furnace body 4. The parallel airflow at the upper end of the furnace body 4 will be guided by the guide plate 5 to form a vertical airflow, and collide with the parallel airflow on the lower side, thereby increasing the gas disturbance in the middle section of the furnace body 4 and making the process gas sweep across the surface of the silicon wafer, further improving the square resistance uniformity of the middle section of the silicon wafer.

[0049] According to a further optimized solution, a quartz reaction tube 9 is fixedly provided on the inner wall of the furnace body 4 , and the quartz boat carrying the silicon wafers is subjected to resistance diffusion in the quartz reaction tube 9 .

[0050] The following is a detailed description of the specific use and beneficial effects of the diffusion furnace:

[0051] Before the diffusion process, the furnace door 1 together with the insulation board 3 is opened under the action of the driving structure, and the feeding mechanism feeds the quartz boat carrying the silicon wafers into the quartz reaction tube 9, and the feeding mechanism withdraws, the furnace door 1 is closed, and the edge of the insulation board is in contact with the furnace body 4; during the diffusion process, the furnace body 4 is electrically heated, and at the same time, the process gas is input into the air inlet pipe 7 at the tail of the furnace, and the process gas is diverted by the diversion structure 6, and the process gas is disturbed by the guide plate 5. After the process gas reaches the insulation board 3, it is concentrated through the through hole 31 between the insulation board 3 and the furnace body 4 and then discharged from the outlet pipe 8.

[0052] The flow distribution structure 6 has the function of evenly distributing the gas in the air inlet pipe 7 at the furnace tail, the flow guide plate 5 has the function of counteracting the airflow in the middle section of the furnace, and the heat insulation plate 3 can prevent the temperature gradient at the furnace mouth from being affected by the need for cooling due to the airtightness requirement of the furnace door, and at the same time has the function of buffering and guiding the airflow reaching the furnace mouth. This solution has the advantages of being easy to implement, simple to operate, and being able to effectively improve the uniformity of silicon wafers at the furnace mouth, furnace middle, and furnace tail sections of the diffusion furnace.

[0053] Second embodiment

[0054] like Figure 7 As shown, the difference between this embodiment and the first embodiment is that a conical guide portion 65 is provided at the right end of the second splitter plate 63 .

[0055] When the process gas flow rate is small, the airflow on the side walls of the furnace body 4 and both sides of the first diverter plate 62 will still show a relatively low process gas concentration. In order to better divert the process gas, a conical guide portion 65 is provided at the right end of the second diverter plate 63 to guide the process gas to the side walls of the furnace body 4 and both sides of the first diverter plate 62, so that the process gas is dispersed more evenly.

[0056] Third embodiment

[0057] like Figure 8 As shown, the difference between this embodiment and the first embodiment is that heating parts 66 are provided at the upper and lower ends of the second diverter plate 63 .

[0058] The process gas introduced into the furnace body 4 needs to be preheated. Since the diverter plate of this solution is placed horizontally, an electric heater can be placed on the diverter plate, such as an electric heating wire. When the electric heating wire is placed on the heating plate, not only can the temperature of the process gas be increased, but the electric heating can also increase the disturbance of the process gas and further disperse the process gas. Preferably, in this solution, heating parts 66 are provided at the upper and lower ends of the second diverter plate 63, which can effectively increase the concentration of the process gas in the airflow on the side wall of the furnace body 4 and on both sides of the first diverter plate 62.

[0059] Fourth embodiment

[0060] like Fig. 9 As shown, the difference between this embodiment and the first embodiment is that the guide plate 5 can be configured to be flippable and freely retractable.

[0061] When the incoming gas flow rate changes, or the position of the silicon wafer to be diffused in the diffusion furnace changes, or the overall height of the silicon wafer placed in the diffusion furnace changes, more process gas can be disturbed above the silicon wafer by changing the drainage direction of the guide plate 5 or adjusting the length of the guide plate 5, thereby improving the uniformity of the square resistance of the silicon wafer.

[0062] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0063] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A diffusion furnace capable of improving the uniformity of square resistance of silicon wafers, characterized in that: The furnace comprises a furnace door (1), a furnace body (4), an air inlet pipe (7), an air outlet pipe (8) and a heat insulation part, wherein one side of the furnace body (4) is open, the furnace door (1) is installed at the opening of the furnace body (4), one end of the furnace door (1) is hinged to the furnace body (4), the air inlet pipe (7) and the air outlet pipe (8) are respectively connected to the furnace body (4), there are at least two air inlet pipes (7), and the heat insulation part is movably arranged on one side of the furnace body (4) close to the furnace door (1); The heat insulation part is a heat insulation board (3), a through hole (31) is provided in the middle of the heat insulation board (3), and the outer edge of the heat insulation board (3) is in contact with the inner wall of the furnace body (4); It also comprises a connecting rod (2) and a stopper (41), one end of the connecting rod (2) being fixedly connected to the furnace door (1), the upper end of the furnace door (1) being hinged to the furnace body (4), the other end of the connecting rod (2) being fixedly connected to the heat insulation board (3), the lower side of the inner wall of the furnace body (4) protruding upward to form a stopper (41), the stopper (41) comprising a coupling surface (411) and a stopper surface (412), the coupling surface (411) being in contact with the lower edge of the heat insulation board (3), and the stopper surface (412) being in contact with the side of the heat insulation board (3), so as to limit the heat insulation board (3) from moving to a side away from the furnace door (1); The air outlet pipe (8) is in communication with the lower end of the furnace body (4), and the air outlet pipe (8) is arranged between the furnace door (1) and the heat insulation board (3); It also includes a flow dividing structure (6) which is arranged on the side away from the furnace door (1), and the flow dividing structure (6) divides the furnace body (4) into a plurality of chambers step by step; The flow dividing structure (6) comprises a fixed rod (61) and a plurality of flow dividing plates, wherein the plurality of flow dividing plates are arranged in parallel and are vertically fixedly connected to the fixed rod (61), the two ends of the fixed rod (61) are fixedly connected to the furnace body (4), and the side edges of the flow dividing plates are fixedly connected to the side walls of the furnace body (4); The plurality of diverter plates include a first diverter plate (62), two second diverter plates (63), and four third diverter plates (64). The plurality of diverter plates are aligned and arranged near one end of the furnace door (1). The length of the second diverter plate (63) is between the length of the first diverter plate (62) and the length of the third diverter plate (64). The length of the third diverter plate (64) is less than the length of the second diverter plate (63). The first diverter plate (62) is arranged on the axis of the furnace body (4). The two second diverter plates (63) are respectively arranged on the axes of the two air inlet pipes (7). The third diverter plate (64) is arranged on the adjacent two sides of each of the second diverter plates (63). The spacing between the plurality of diverter plates is equal.

2. A diffusion furnace capable of improving the uniformity of square resistance of silicon wafers according to claim 1, characterized in that: Two air inlet pipes (7) are arranged on the end surface of the furnace body (4) away from the furnace door (1), and the two air inlet pipes (7) are symmetrically arranged relative to the axis of the furnace body (4).

3. The diffusion furnace capable of improving the uniformity of square resistance of silicon wafers according to claim 1, characterized in that: It also includes a guide plate (5) which is fixedly arranged above the middle section of the inner wall of the furnace body (4).

4. A diffusion furnace capable of improving the uniformity of square resistance of silicon wafers according to any one of claims 1 to 3, characterized in that: A quartz reaction tube (9) is fixedly arranged on the inner wall of the furnace body (4).

Images